Limpkin's blog - Comments<div>An electronics geek blog, dedicated to sharing and open source. Check out my stores: <a href="https://lectronz.com/stores/stephanelec" hreflang="en" title="Lectronz store">EU</a> / <a href="https://www.tindie.com/stores/stephanelec" hreflang="en" title="tindie store">EU & US</a>.</div>2024-03-14T19:40:24+00:00Mathieuurn:md5:51de6a3d917257edeff5a252fe925b02DotclearCDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:11d535959a94520dcf89c0fab20d1f3a2024-03-14T17:24:32+00:002024-03-14T17:24:32+00:00limpkin<p>Hi Dave!<br>
1) FAT, 512 bytes<br>
2) just to make it clear, at the moment the logging functionality is not implemented so you'll need to compile the firmware yourself. you'll need to use either my tool or the others i mentioned to flash the new firmware. no worries about bricking, you'll always be able to reflash the board<br>
3) they drive the MCU BOOT0 and RST pins :)</p>CDM324 Doppler Speed Sensor, with FFTs! - Daveurn:md5:f5a8c76d9754fdab71abb7d5cc9051d12024-03-13T10:45:24+00:002024-03-13T10:45:24+00:00Dave<p>Hi, you have done some great work here and it’s much appreciated!<br>
I am trying to use the backpack board to record to the SD. You mentioned some additional software above, and to format the card with a 512 block size.<br>
My questions are:<br>
1) Should I format the card as NTFS, FAT, or ExFat file system, and do you mean 512bytes or kilobytes?<br>
2) Do I need to use your reflashing PC software to install onto the board the SDcard software you linked in the comment above? I’m nervous about overwriting the software already on the board so any specific instructions would be welcome .<br>
3) What do the two buttons on the board do?<br>
Thank you!</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:d5786cbb95a01829565b539ee4a34ffd2024-03-05T20:07:40+00:002024-03-05T20:07:40+00:00limpkin<p>@SeanG: I don't think integrating the speed would provide reliable distance measurement for long distances...</p>CDM324 Doppler Speed Sensor, with FFTs! - SeanGurn:md5:68adcf08cc918afebef5f31b1ef2ac3b2024-03-05T04:27:30+00:002024-03-05T04:27:30+00:00SeanG<p>Would it be possible to modify the output to give distance travelled, assuming the sensor is pointed towards the ground at 45 degrees?</p>
<p>In the application I have in mind, some output filtering would be needed to take into account an uneven surface (ploughed field).</p>
<p>Speeds travelled will be between 1 - 6 kph.</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:a3db8a880b2320537a3976e1b48e60292024-02-29T18:40:32+00:002024-02-29T18:40:32+00:00limpkin<p>@Homer: I honestly don't see why not :)</p>CDM324 Doppler Speed Sensor, with FFTs! - Homerurn:md5:08dbcddff7a66f5e027878d03240c5b12024-02-28T22:06:36+00:002024-02-28T22:06:36+00:00Homer<p>Hi, the new version looks very nice!</p>
<p>I am interested in measuring the speed of water flowing inside an irrigation canal.</p>
<p>The sensor will be positioned a little bit above the surface, at an angle.</p>
<p>Is it possible to measure speeds as low as 2.5km/h?</p>Repairing a Pair of Audioengine A5 Speakers - emilurn:md5:2551a0a5da64470ea2c62b154fe4fc7f2024-02-22T07:21:53+00:002024-02-22T07:21:53+00:00emil<p>thankyou, this article help me alot... my ae A5 got same problem</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:d109238ae896602d110c98290f998ea32024-02-21T18:12:28+00:002024-02-21T18:12:28+00:00limpkin<p>@mike: could you let me know the errors? 3.12 and 3.11 should work<br />
your project should work indeed, simply grab the speed through uart :)</p>CDM324 Doppler Speed Sensor, with FFTs! - mikeurn:md5:28a0e1a7d39b40bd8221671f190e20612024-02-21T16:06:02+00:002024-02-21T16:06:02+00:00mike<p>Trying to load the Gui nevertheless recieve all kinds of errors can you let me know to what Python version it works ?</p>
<p>Python 3.12 and 3.11 gives errors on treats and the 2.7 does not allow pip install</p>
<p>Reffering to my other Question,<br />
The intention would be to add a esp32 to grab the speed which i hope is visable in the serial</p>
<p>Which i would like to display the speed on a 7 segment ledstrip display<br />
<a href="https://youtu.be/r_yobwaBWr0?t=766" title="https://youtu.be/r_yobwaBWr0?t=766" rel="ugc nofollow">https://youtu.be/r_yobwaBWr0?t=766</a></p>
<p>Bassically building my own maximum speed display</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:c6268732ef951fe5aca445b31bb6516a2024-02-21T15:33:18+00:002024-02-21T15:33:18+00:00limpkin<p>@Craig: yes of course :)<br />
@mike: definitely possible as you'd just need the UART connection. I'm not sure what you mean by your second question?</p>CDM324 Doppler Speed Sensor, with FFTs! - mikeurn:md5:2378fdc13f10db3f5e10856ffe2ec1672024-02-20T19:19:12+00:002024-02-20T19:19:12+00:00mike<p>Is it possible to just steer the device without the extender board true a ESP32 ? which gives a solid 3.3v from the board.<br />
And it would be possible then to steer a 7 segment led strip board?</p>
<p>Gruss aus Zuri</p>CDM324 Doppler Speed Sensor, with FFTs! - Craigurn:md5:a4080f27d4fc7f0c7da35bdbc45d0ec22024-02-20T17:19:40+00:002024-02-20T17:19:40+00:00Craig<p>Could this device be used with a Raspberry Pi, instead of an Arduino?</p>Making the Electronics for a 24GHz Doppler Sensor - limpkinurn:md5:929e74a147be42147532801dd0f38c842024-01-28T22:52:02+00:002024-01-28T22:52:02+00:00limpkin<p>@Greg: that's correct yes :)</p>Making the Electronics for a 24GHz Doppler Sensor - Gregurn:md5:9e6c86b0ef003c9e7fa004a8de5ad61e2024-01-27T00:43:17+00:002024-01-27T00:43:17+00:00Greg<p>Hi @limpkin, thank you for the great project. Before you rolled out the new version that takes advantage of FFT, I started looking for a way to adapt this circuit to get an analog signal out of it and perform FFT on a MC. To achieve that, I just removed the comparator branch, and it worked with a 5V MC (Arduino Uno). Now I'm trying to feed the signal to a ESP07 which operates at 3.3V and takes no more than 1V on its ADC. Am I getting it right that only R2 and R3 values need to be modified, so that the analog signal on VOUTB of the amplifier is centered around 0.5V?</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:997f8642215e875a814f36e2c6f6c5602023-12-10T08:40:58+00:002023-12-10T08:40:58+00:00limpkin<p>@Johan: it'll work well inside a box :)</p>CDM324 Doppler Speed Sensor, with FFTs! - Johanurn:md5:31ffe4292e2ef699b150f48d2308b67a2023-12-07T09:04:31+00:002023-12-07T09:04:31+00:00Johan<p>Hi<br />
I recently bought 3 devices for testing with my MCU MKR1310, just a quick question is it possible to have the sensor inside a box to weatherproof the sensor or would it not work well inside a box?</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:7ca0c1a071b0a6eab86f29c4531dd9d32023-12-05T13:02:08+00:002023-12-05T13:02:08+00:00limpkin<p>@Dave: plastic or glass boxes will indeed work! Your plan sounds like a good one.</p>CDM324 Doppler Speed Sensor, with FFTs! - Daveurn:md5:54dac357f8a7231dfff34cdd36b2fe5c2023-12-03T15:00:49+00:002023-12-03T15:00:49+00:00Dave<p>Hey, I also purchased the kit from your Tindie store and am eager to get my project to monitor the average speeds of the road outside our house off the ground. I was just wondering if you have any recommendations about waterproofing and/or enclosures. From my understanding plastic and glass should be transparent at these frequencies so I was thinking of just using a normal plastic project box and sealing it all up with silicone before installing it outside. I'll probably use PoE to get power and data to/from the box but will just seal that exit point as well.</p>Assembling a 48V 18650 Cell-Based Battery - Wallyurn:md5:6203935728222b878e6f45e4e5c539902023-11-30T07:06:15+00:002023-11-30T07:06:15+00:00Wally<p>Nice! I have a non functional ego mower battery pack that won't charge anymore, it probably has only one or two bad cells, and the BMS and charger display a fault code. I'm hoping to get it going again and maybe starting a little side hustle rebuilding them. I also want to do my own E-bike packs. I would go about testing/balancing the cells at more like 10 at a time, rather than 100. But still great info. Thanks</p>CDM324 Doppler Speed Sensor, with FFTs! - limpkinurn:md5:b92504e1ba471334b4d5295bb36a12da2023-11-08T20:08:35+00:002023-11-08T20:08:35+00:00limpkin<p>@vagyer: thanks for the kind words! I've updated the readme to mention the tying to ground trick :).<br />
Unless you serve at more than 200km/h I don't think you need to make any modification.... however if you see that the speed is not picked up, maybe we could modify the high pass filter to filter speeds below 50km/h. to be honest I'm not sure if how sensitive the radar will be</p>